KR101974591B1 - Eco-friendly and high functional solidifying composition for point foundation - Google Patents

Abstract

The present invention is to be applied to a point foundation for improving the durability during construction, such as a middle-low story structure, and is environmentally friendly and highly functional for points based on workability, quick hardness, durability and high toughness with less risk of leaching of harmful substances and soil contamination And to fire-retardant compositions.
The present invention relates to an environmentally friendly high performance fire retardant composition for use on a point basis, wherein the fire retardant composition is composed of 100 parts by weight of a blast furnace slag fine powder, 5 parts by weight of a natural anhydrous gypsum 5 To 50 parts by weight; 0.5 to 500 parts by weight of petroleum coke desulfurization gypsum; And 5 to 500 parts by weight of a natural mineral filler containing at least one selected from a limestone fine powder, a feldspar fine powder, a fine silica powder, a granite fine powder and a dolomite fine powder; Wherein the Petro Coke desulfurization gypsum has a CaO content of 40 to 70 wt% based on 100 wt% of petrocoke desulfurized gypsum, an SO ₃ content of 10 to 30 wt% of petroleum gypsum desulfurized gypsum based on 100 wt% Wherein the composition further comprises 0.1 to 10 parts by weight of organic step fiber relative to 100 parts by weight of the hight building composition.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an Eco-friendly and high functional solidifying composition for point foundation,

The present invention is to be applied to a point foundation for improving the durability during construction, such as a middle-low story structure, and is environmentally friendly and highly functional for points based on workability, quick hardness, durability and high toughness with less risk of leaching of harmful substances and soil contamination And to fire-retardant compositions.

Generally, pile foundation method is used for soft ground reinforcement. These file bases are very effective for structures with high loads such as high-rise buildings. However, it is inefficient and inefficient to construct piles up to weathered rocks in a medium - low - rise structure with a load of only 30 ~ 35tf / ㎡.

In order to solve these problems, a point foundation method has been widely used to improve the grounding ability by replacing the ground by injecting an inorganic chemical solution and mixing with a paper board as a method for the grounding of a low-rise structure.

The above-mentioned chemical solution injection method is a method of injecting a filling material, which is a suspendable or solution-type chemical solution having a proper fluidity in a soft ground and capable of being cured after a predetermined time, with the pressure of a pump to fill voids or cracks in the ground, Reduces permeability. Or by mixing the above-mentioned filler with a soft ground, stirring the mixture, and consolidating the filler to improve the endurance.

For this purpose, cement liquid, mortar liquid, water glass liquid and the like are used as an injection material.

In general, cement is used as the main binder in the generally used chemical reinforcement solution for ground reinforcement. However, cement can cause environmental pollution due to strong alkali and hexavalent chromium in the ground, and causes excessive volume shrinkage during hydration reaction.

Several techniques have been proposed to overcome the problem of using existing cement as a grouting filler.

For example, Korean Patent Registration No. 10-0699430 discloses a technique in which the occurrence of bleeding is reduced by adding cement as a main material and aluminum sulfate as a flocculant to grout (liquid A) containing bentonite, a dispersant and a retarder as an admixture, (B solution) to B solution (Solution A) to give expandability by using the foaming effect due to the chemical action of aluminum powder and cement. However, the bentonite presented in this technology is an expensive product that is heavily dependent on imports. Since aluminum powder is a fine particle and has a light specific gravity, it may be fatal if a person inhales due to scattering during handling. Therefore, even when it is used as a foaming agent in mortar, it is a material to be handled in a limited work space provided with a dustproof facility and may have a problem in that it is not mixed with bentonite when producing a suspension mixed with water.

Further, in Korean Patent No. 10-0886220, a filling material (liquid A) is composed of Portland cement or a mixture of Portland cement and blast furnace slag cement, and the quick-setting (liquid B) is a technique of mixing sodium silicate with an acidic chemical . This technique is to neutralize the acidic solution by mixing it to lower the alkali of the sodium silicate used as a quick-setting agent. However, since cement is the main raw material, it is not different from existing technology.

In Korean Patent No. 10-0804807, aluminate is heat-treated at a temperature of 600 to 700 占 폚 to obtain 35 to 65% of a powdery precipitate pulverized to have a powder degree of 4,500 to 5,500 cm2 / g, calcium sulfoaluminate powder 15 (A) composed of a cement composition (A) composed of a cement composition (A) composed of a cement composition (A) consisting of a cement composition 50 to 70%, and 30 to 50% of slag fine powder (B). The microcement generally has a powdery degree of 6,000 cm < 2 > / g or more, which is considerably high. In addition, since there are seven kinds of raw materials to be used for the water-dispersible material (liquid A), there are many problems in production of products for practical use.

In order to solve the above-mentioned problems, the present invention provides an environmentally friendly high functionality fire-resistant composition for point-based use, which has less risk of leaching of harmful substances and soil pollution.

An object of the present invention is to provide an eco-friendly, high-performance fire-resistant composition for points based on which the burden of the raw material cost is small and can lead to active commercialization.

The present invention seeks to provide a point-based environmentally friendly, highly functional fire-retardant composition having a workability, a rapid hardness, a durability and a high toughness.

According to a preferred embodiment of the present invention, there is provided an environmentally friendly high performance fire retardant composition for use on a point base, wherein the fire retardant composition comprises 5 to 50 parts by weight of natural anhydrous gypsum having a particle size of 50 탆 or less based on 100 parts by weight of the blast furnace slag fine powder ; 0.5 to 500 parts by weight of petroleum coke desulfurization gypsum; And 5 to 500 parts by weight of a natural mineral filler containing at least one selected from a limestone fine powder, a feldspar fine powder, a fine silica powder, a granite fine powder and a dolomite fine powder; Wherein the Petro Coke desulfurization gypsum has a CaO content of 40 to 70 wt% based on 100 wt% of petrocoke desulfurized gypsum, an SO ₃ content of 10 to 30 wt% of petroleum gypsum desulfurized gypsum based on 100 wt% Wherein the composition further comprises 0.1 to 10 parts by weight of organic step fiber relative to 100 parts by weight of the hight building composition.

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According to another preferred embodiment of the present invention, the natural mineral filler has a particle diameter of 50 탆 or less.

According to another preferred embodiment of the present invention, 0.5 to 10 parts by weight of a quick-setting aluminate-based quick-setting admixture is further added to 100 parts by weight of the blast furnace slag fine powder.

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According to another preferred embodiment of the present invention, there is provided an environmentally friendly high functionality fire extinguishing composition for a point base, which further comprises 0.5 to 500 parts by weight of fly ash per 100 parts by weight of the blast furnace slag fine powder.

According to another preferred embodiment of the present invention, 0.01 to 10 parts by weight of a liquid or powdery fluidizing agent is further added to 100 parts by weight of the fire-retardant composition.

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The present invention has the following effects.

First, since blast furnace slag is used as a binder instead of Portland cement, it is possible to solve the problem of the elution of harmful substances such as carbon dioxide and the environmental pollution caused thereby.

Second, the industrial byproducts generated in the circulating fluidized bed boiler are used as a stimulant for blast furnace slag powder to express strength, and natural minerals are used as stimulants and fillers. Therefore, it is possible to reduce production cost by reducing cement usage, and to reduce raw material cost burden by using natural resources. At the same time, problems of energy exhaustion and environmental pollution caused by the release of harmful heavy metals can be solved at the same time.

Third, the latent hydraulic properties of the blast furnace slab powder can be initially activated by the combined stimulation of natural anhydrous gypsum and desulfurized gypsum, which have no harmful components.

Fourth, the inclusion of quick hard aluminate type fasteners can provide early compressive strength even in the winter season or when the water content is high.

Fifth, when staple fibers, especially organic staple fibers, are contained, it is effective for crack prevention and seismic reinforcement by securing high toughness.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments.

The present invention relates to an environmentally friendly high functionality fire retardant composition for use on point bases, comprising blast furnace slag fine powder; Natural anhydrous gypsum; Petro coke desulfurization plaster; And a natural mineral filler containing at least one selected from the group consisting of a fine powder of limestone, a fine feldspar powder, a fine silica powder, a fine granite powder, and a dolomite fine powder; And a control unit.

The present invention relates to a point foundation method for enhancing the foundation resistance of a medium-low-rise structure or the like by substituting a ground by injecting an inorganic chemical solution and mixing with a paperboard.

The present invention provides a point-based fire-resistant composition having low workability, quick hardness, durability and high toughness while minimizing the risk of leaching of harmful substances and soil contamination.

Generally, the Portland cement used as a binder is very high in energy consumption because it is heated to a high temperature in a firing furnace during production. In addition, the calcination step of limestone and the burning of fossil fuels produce enormous amount of carbon dioxide in the calcination process, which is a great environmental problem.

In the present invention, blast furnace slag is used as a binder to replace portland cement.

The blast furnace slag fine powder is obtained by quenching slag in a hot molten state generated as a by-product in a steelmaking blast furnace process with water and then pulverizing the by-product to a surface area of 3,000 cm 2 / g or more.

The blast furnace slag fine powder is a latent hydraulic material that forms an amorphous coating upon contact with water and does not hydrate itself. Therefore, the strength of blast furnace slag is increased in the long - term age, but the property of blast furnace slag itself is weak in the early age.

Therefore, in the present invention, the amorphous film formed by the contact of the fine powder of the blast furnace slag with water is destroyed by the combined stimulating effect of the natural anhydrous gypsum and the desulfurized gypsum. Thus, the latent hydraulic properties of the blast furnace slag fine powder can be initially activated.

The natural anhydrous gypsum serves as a sulfate stimulant for the blast furnace slag fine powder, and because it has no harmful components, it greatly reduces the toxicity of the fire.

The natural anhydrous gypsum can have a particle diameter of 50 탆 or less.

In order to activate the hydration reaction of the fine blast-furnace slag powder at an early stage, it is preferable to grind the natural anhydrous gypsum to a particle size of 50 탆 or less.

The petrocoke desulfurization gypsum is discharged from a boiler in which the petroleum coke is mixed with limestone in a circulating fluidized bed boiler using petroleum coke as a main fuel and desulfurized in the furnace.

Specifically, the desulfurization process of the circulating fluidized bed boiler will be described. When limestone is injected into the combustion chamber and burned together with the fuel, sulfur dioxide and limestone in the combustion gas react in the furnace to remove sulfur in the combustion gas and produce anhydrous gypsum. The limestone, which has not reacted with sulfur, is decarboxylated and transferred to lime.

The petrocoke desulfurized gypsum thus produced is a strong alkali substance having a pH of 12.0 or higher and exhibits excellent performance as a stimulant for blast furnace slag fine powder.

When water is usually added to the blast furnace slag powder, an amorphous film is formed on the surface, and the internal Ca ^{2 +} , Al ^{3 +,} etc. are not eluted. However, when petrocoke desulfurization gypsum is added, the CaO component contained therein is converted into Ca (OH) ₂ by reacting with water. The resulting OH ^- and the SO ₄ ^2- component generated during the desulfurization process break down the amorphous coating of the blast furnace slag powder to facilitate the elution of Ca ^{2 +} , Al ^{3 +,} and the like. The eluted ions generate CaO-SiO ₂ -H ₂ O-based hydrates and the like, thereby densifying the structure inside the hydrate, thereby improving and improving the compressive strength of the solidified body.

The filler is used to fill micropores inside the injection material. In the present invention, a natural mineral filler is used to reduce toxicity.

The natural mineral filler may have a particle diameter of 50 탆 or less.

It is preferable that the natural mineral filler is pulverized into a fine powder having a particle diameter of 50 탆 or less in order to fill the internal microvoids tightly.

The point-eco-friendly high performance fire-fighting composition for point-of-use according to the present invention comprises 5 to 50 parts by weight of natural anhydrous gypsum, 0.5 to 500 parts by weight of petroleum gypsum desulfurization gypsum, 5 to 500 parts by weight of natural mineral filler, . ≪ / RTI >

If the amount of the natural anhydrous gypsum is less than 5 parts by weight, the effect of stimulating the sulfate is not exhibited. If the amount is more than 50 parts by weight, gypsum components that have not reacted with the blast furnace slag powder remain in large amounts,

If the amount of the Petro Coke-desulfurized gypsum is less than 0.5 part by weight, the blast furnace slag powder is not properly provided. If the blending amount exceeds 500 parts by weight, the content of the blast furnace slag is relatively decreased and the strength of the blast furnace component is excessively decreased.

If the amount of the natural mineral filler is less than 5 parts by weight, the filling effect is lowered to deteriorate the flowability and strength, and the toxicity reduction effect is deteriorated. If the amount is more than 500 parts by weight, the natural mineral filler is only present in mineral form.

In this case, 0.5 to 10 parts by weight of a quick-setting aluminate-based quick-setting admixture may be further added to 100 parts by weight of the blast furnace slag fine powder.

When the rapid hard aluminate type quick-setting admixture is included, the compressive strength can be exhibited early even in the winter season or when the water content is high.

The quick-hard aluminate-based quick-setting admixture can be generally used in the market, but it is economical when the by-products obtained in the reduction process of the steelmaking slag are used.

If the amount of the quick-setting aluminate-based rapid setting agent is less than 0.5 parts by weight, it is difficult to expect a sharpening effect. If the amount is more than 10 parts by weight, the conveying line may become clogged during slurry transfer due to initial expansion and swelling.

In addition, 0.5 to 500 parts by weight of fly ash may be further added to 100 parts by weight of the blast furnace slag fine powder.

The fly ash acts as a stimulant for blast furnace slag fine powder.

Unlike pulverized coal boiler coal ash discharged from a general thermal power plant having a separate desulfurization facility, the fly ash has a high content of CaO and SO ₃ because desulfurization is performed in the furnace by mixing limestone. It is difficult to use it as a concrete admixture but it hardens the soil with high function.

If the amount of the fly ash is less than 0.5 part by weight, the effect of the fly ash is difficult to exhibit. If the amount of the fly ash is more than 500 parts by weight, the content of the blast furnace slag is decreased.

Further, 0.01 to 10 parts by weight of a liquid or powdery fluidizing agent may be further added to 100 parts by weight of the fire-retardant composition.

The liquid or powder type fluidizing agent has an effect of improving the fluidity and improving the workability in a soil having a high water content or a site having a high inflow of groundwater.

The liquid or powder type fluidizing agent may be any one or a mixture of two or more selected from the group consisting of naphthalene type, melamine type, amine type, lignin type and polycarboxylic type.

When the liquid or powder type fluidizing agent is less than 0.01, there is no fluidity improving effect. And if it is more than 10, the fluidity becomes excessively large, and material separation may occur, resulting in low economic efficiency.

And 0.1 to 10 parts by weight of short fibers relative to 100 parts by weight of the composition. Wherein the staple fibers may be organic staple fibers.

The staple fibers are mixed in order to cope with shear stress at the site where seismic retrofitting is required or the liquefaction behavior is expected to be high and to secure high toughness.

Organic stepped fibers have very high resistance to carbon-containing solvents, oils, salts, and alkalis.

In addition, the hydrophilic structure having a hydroxyl group on the fiber surface is well dispersed in a liquid phase, and has excellent elastic modulus and adhesion to powder components.

In addition, it is effective in suppressing microstructures and stabilizing microcracks due to its relatively small diameter, which is very effective in increasing mechanical properties through crosslinking of fibers and is effective in suppressing cracks caused by fatigue and impact load.

The staple fiber is preferably a vinyl alcohol staple fiber having a specific gravity of 1.1 to 1.3 g / cm 2, a diameter of 9 to 12 탆, a tensile strength of 7,000 to 9,000 kgf / cm 2 and a length of 3 to 8 cm.

If the amount of the staple fibers is less than 0.1 part by weight, the effect of suppressing the firing cracks is insignificant. When the amount of the staple fibers is more than 10 parts by weight, the flowability is lowered, and the compressive strength is lowered.

Next, the effect of the present invention on the point-based environmentally friendly high performance fire retardant composition will be described.

Comparative Example

100 parts by weight of water was added to 100 parts by weight of the first kind of cement, followed by wet mixing to prepare a homogeneous slurry mixture. 9 specimens of Φ10 cm × 20 cm size were prepared and cured at 20 ° C., and the strengths were measured at 7 days, 28 days and 90 days at the age of.

Example

5 parts by weight of alumate solids, 10 parts by weight of natural anhydrous gypsum, 20 parts by weight of limestone fine powder having an average particle diameter of 23 mu m, and a CaO content of 58.9% by weight, based on 100 parts by weight of the blast furnace slag fine powder having a specific surface area of 4,360 cm & 50 parts by weight of an in-furnace desulfurization-type circulating fluidized bed boiler coke-desulfurized gypsum having an SO ₃ content of 25.8% by weight, 30 parts by weight of a coal gasification furnace desulfurization type circulating fluidized bed boiler having a CaO content of 38.9% by weight and an SO ₃ content of 13.8% by weight Dry mixing was carried out. 100 parts by weight of water was further added to 100 parts by weight of the mixture, followed by wet mixing to prepare a homogeneous slurry mixture. 9 specimens of Φ10 cm × 20 cm size were prepared and cured at 20 ° C., and the strengths were measured at 7 days, 28 days and 90 days at the age of.

Test methods and results of specimens

As shown in Table 1 below, the compressive strength test was carried out by the uniaxial compressive strength test method of KS F 2343. The pH and heavy metal leaching test were carried out by collecting a part after 28 days compressive strength measurement.

Experiment Way Remarks Compressive strength KS F 2343 Uniaxial Compressive Strength Test Method Heavy metal leaching Waste process test standard Heavy metal dissolution test method pH Waste process test standard

division Compressive strength 7 days (MPa) Compressive strength 28 days (MPa) Compressive strength 90 days (MPa) Comparative Example 9.56 21.20 24.20 Example 11.78 24.64 29.43

(1) Change in uniaxial compressive strength

Table 2 shows the uniaxial compressive strengths of Comparative Examples and Examples. As can be seen from the above, the examples using the blast furnace slag fine powder, aluminate flocculant, natural anhydrous gypsum, natural mineral filler, circulating fluidized bed boiler coke desulfurization gypsum, and circulating fluidized bed boiler fly ash were compared with Comparative Example 1, cement was significantly higher than that of the first cement in the 90 days old age as well as the 7 days and 28 days strength.

Therefore, it can be seen that the fire-resistant composition of the present invention can exhibit performance to replace the first-type cement used in the ground reinforcement method.

(2) Extraction of heavy metals

The results of the heavy metal leaching experiment are shown in Table 3 as follows.

division
pH KSLT Hexavalent chromium Copper Mercury cadmium lead arsenic Acceptance criteria 12.5 1.5 3.0 0.005 0.3 3.0 1.5 Comparative Example 12.6 0.783 0.745 Non-detection 0.051 0.258 0.077 Example 11.8 Non-detection Non-detection Non-detection Non-detection Non-detection Non-detection

As shown in Table 3, pH and heavy metal leaching test results showed that the pH of the comparative example exceeded the allowable limit value of 12.5. On the contrary, in the case of the embodiment, the result satisfies the allowable standard within 11.8.

Therefore, when cement is used, the possibility of contamination of the soil due to the leaching of the strong alkali component is high.

In the case of hexavalent chromium, more than 50% of the standard value was eluted. However, the embodiment of the present invention did not detect any heavy metals as well as hexavalent chromium.

 Therefore, the hot-fire composition of the present invention can be used as a stimulant of fine powder of blast furnace slag powder in a large amount of industrial by-products generated in a circulating fluidized bed boiler, and by using natural minerals as a stimulant and filler, It can usually replace cement or minimize its use. In addition, it can be said that it is possible to provide an eco-friendly ground filler material capable of solving both natural resource and energy exhaustion problem, carbon dioxide emission, strong alkali leaching, and environmental pollution problem by leaching harmful heavy metal as well as reduction of production cost by reduction of cement usage amount.

The petrocoke desulfurized gypsum can be constituted such that the CaO content is 40 to 70% by weight based on 100% by weight of Petro coke desulfurization gypsum.

If the CaO content of Petro Coke desulfurization gypsum is less than 40 wt%, the amount of CaO present in pure CaO itself is insufficient, except for CaO content of about 20 wt% in the form of CaCO ₃ and CaSO ₄ .

That is, since the pure CaO reacts with water and is converted into Ca (OH) ₂ , the amount of generated OH ^- ion becomes insufficient, so that it is difficult to destroy the amorphous film of the blast furnace slag fine powder in a short period of time.

In addition, the pure CaO present in Petro Coke desulfurization gypsum reacts with water and absorbs, exotherms and expands as shown in the following reaction formula, and when it becomes Ca (OH) ₂ , its volume expands about 1.99 times.

(Reaction formula) CaO + H ₂ O → Ca (OH) ₂ + 15.6 kcal / mol

The pure CaO component reacts with water to transition to Ca (OH) ₂ , and at the same time, promotes potential hydraulic and pozzolanic reactions by compensating for volumetric shrinkage of the solidified body due to temperature rise. When the pure CaO content is insufficient, It becomes difficult to perform.

If the CaO content of the petro coke desulfurized gypsum exceeds 70 wt%, the CaO content existing in the pure CaO form is excessively absorbed to excessively absorb water, resulting in excessive generation of heat and expansion and cracking.

The petrocoke desulfurized gypsum can be configured so that the SO ₃ content is 10 to 30% by weight based on 100% by weight of Petro coke desulfurization gypsum.

The petro coke desulfurization gypsum is difficult to strength by SO ₃ content is less than 10% by weight of SO ₃ content of the blast furnace which can stimulate the slag is low.

If the content of SO ₃ is more than 30% by weight, an excessive amount of SO ₃ that does not react with the blast furnace slag powder may exist, and the strength may be lowered.

Claims (11)

The present invention relates to an environmentally friendly high functionality fire retardant composition used on a point basis,
The fire retardant composition comprises 5 to 50 parts by weight of natural anhydrous gypsum having a particle size of 50 탆 or less, based on 100 parts by weight of the blast furnace slag fine powder; 0.5 to 500 parts by weight of petroleum coke desulfurization gypsum; And 5 to 500 parts by weight of a natural mineral filler containing at least one selected from a limestone fine powder, a feldspar fine powder, a fine silica powder, a granite fine powder and a dolomite fine powder; , ≪ / RTI &
The Petro Coke desulfurization gypsum has a CaO content of 40 to 70% by weight based on 100% by weight of Petro coke desulfurization gypsum, an SO ₃ content of 10 to 30% by weight based on 100% by weight of Petro coke desulfurization gypsum,
Wherein the hight building composition further comprises 0.1 to 10 parts by weight of an organic stair fiber per 100 parts by weight of the hight building composition.
delete delete The method of claim 1,
Wherein the natural mineral filler has a particle diameter of 50 탆 or less.
delete delete The method of claim 1,
And 0.5 to 10 parts by weight of a quick-setting aluminate-based quick-setting admixture relative to 100 parts by weight of the blast furnace slag fine powder.
The method of claim 1,
And 0.5 to 500 parts by weight of fly ash relative to 100 parts by weight of the blast furnace slag fine powder.
The method of claim 1,
Wherein the composition further comprises 0.01 to 10 parts by weight of a liquid or powdery fluidizing agent relative to 100 parts by weight of the composition. delete delete